Individuals earning income through affiliate links on platforms such as blogs, social media groups, or newsletters may experience uncredited commissions, even when a sale has been completed. This occurs when the merchant's website fails to recognise that the buyer originated from the affiliate's link.
There are six common reasons why these commissions may not be recorded. These include buyers switching devices, which can prevent the tracking cookie from being present on the purchasing device. Short cookie windows, such as Amazon's 24-hour period, can also lead to lost sales if a buyer takes longer to decide.
Last-click attribution, used by many programmes, means a commission can be lost if a buyer clicks another affiliate link, such as from a cashback site or voucher page, before purchasing. Browser settings that block or wipe cookies, or broken links that strip tracking codes, are further causes. Finally, commissions can be tracked but later reversed due to refunds, cancellations, or free trials not converting to paid plans.
Affiliate income for individuals in the UK is generally classified as trading income. If gross trading income exceeds £1,000 in a year, individuals are required to register for Self Assessment and declare it to HMRC.